Cdk8/CDK19 promotes mitochondrial fission through Drp1 phosphorylation and can phenotypically suppress pink1 deficiency in Drosophila.

Cdk8 in Drosophila is the orthologue of vertebrate CDK8 and CDK19. These proteins have been shown to modulate transcriptional control by RNA polymerase II. We found that neuronal loss of Cdk8 severely reduces fly lifespan and causes bang sensitivity. Remarkably, these defects can be rescued by expression of human CDK19, found in the cytoplasm of neurons, suggesting a non-nuclear function of CDK19/Cdk8. Here we show that Cdk8 plays a critical role in the cytoplasm, with its loss causing elongated mitochondria in both muscles and neurons. We find that endogenous GFP-tagged Cdk8 can be found in both the cytoplasm and nucleus. We show that Cdk8 promotes the phosphorylation of Drp1 at S616, a protein required for mitochondrial fission. Interestingly, Pink1, a mitochondrial kinase implicated in Parkinson's disease, also phosphorylates Drp1 at the same residue. Indeed, overexpression of Cdk8 significantly suppresses the phenotypes observed in flies with low levels of Pink1, including elevated levels of ROS, mitochondrial dysmorphology, and behavioral defects. In summary, we propose that Pink1 and Cdk8 perform similar functions to promote Drp1-mediated fission.

Obstetrical Outcomes of Patients with Epilepsy in a Canadian Tertiary Care Center (2014-2020).

BACKGROUND: There is a paucity of data on the obstetrical outcomes of Canadian pregnant patients with epilepsy, which may differ from the average Canadian pregnancy and from other populations of pregnant patients with epilepsy. METHODS: Pregnant patients with epilepsy were identified from a prospectively collected database of patients seen at the maternal-fetal medicine obstetrics program of Mount Sinai Hospital (Toronto, Canada) between January 1, 2014, and November 20, 2020. Pregnancy, delivery, and neonatal outcome data were retrieved from this database and described using 95% binomial confidence intervals. Comparisons of obstetrical outcomes over the same period among the Canadian population average, obtained from publicly available national health data, were done using one-proportion Z-tests for nominal variables and one-sample t-tests for continuous variables. RESULTS: In total, 282 pregnancies, from 224 patients, were included, which resulted in 274 live births. Mean maternal age was 32.8 years (s.d. = 4.6; population average [µ] = 30.9; p < 0.01), and 53% were primiparous (CI95% = 49%-61%; µ = 43%; p < 0.01). The observed rates of obstetrical complications were gestational hypertension 9% (CI95%=6%-13%; µ=7%; p=0.19), gestational diabetes 5% (CI95% = 3%-8%; µ = 9%; p = 0.02), cesarean section 44% (CI95% = 38%-50%; µ = 28%; p < 0.01), postpartum hemorrhage 5% (CI95% = 3%-8%; µ = 0.5%; p < 0.01), stillbirth 1% (CI95% = 0%-2%; µ=1%; p > 0.99), and prematurity 9% (CI95% = 6%-13%; µ = 8%; p = 0.44). CONCLUSION: In this cohort of Canadian pregnant patients with epilepsy from an urban tertiary care center, observed rates of obstetrical complications were rare and no higher than in the Canadian population over the same period, with the exception of cesarean section and postpartum hemorrhage. Future prospective studies that include primary care and rural settings are needed to increase the generalizability of those results.

Hyperpolarized mitochondria accumulate in Drosophila Hipk-overexpressing cells to drive tumor-like growth.

Both functional and dysfunctional mitochondria are known to underlie tumor progression. Here, we establish use of the proto-oncogene Drosophila Homeodomain-interacting protein kinase (Hipk) as a new tool to address this paradox. We find that, in Hipk-overexpressing tumor-like cells, mitochondria accumulate and switch from fragmented to highly fused interconnected morphologies. Moreover, elevated Hipk promotes mitochondrial membrane hyperpolarization. These mitochondrial changes are at least in part driven by the upregulation of Myc. Furthermore, we show that the altered mitochondrial energetics, but not morphology, is required for Hipk-induced tumor-like growth, because knockdown of pdsw (also known as nd-pdsw; NDUFB10 in mammals; a Complex I subunit) abrogates the growth. Knockdown of ATPsynß (a Complex V subunit), which produces higher levels of reactive oxygen species (ROS) than pdsw knockdown, instead synergizes with Hipk to potentiate JNK activation and the downstream induction of matrix metalloproteinases. Accordingly, ATPsynß knockdown suppresses Hipk-induced tumor-like growth only when ROS scavengers are co-expressed. Together, our work presents an in vivo tumor model featuring the accumulation of hyperfused and hyperpolarized mitochondria, and reveals respiratory complex subunit-dependent opposing effects on tumorigenic outcomes.This article has an associated First Person interview with the first author of the paper.

PARP inhibition suppresses the emergence of temozolomide resistance in a model system.

INTRODUCTION: Temozolomide (TMZ) is a life prolonging DNA alkylating agent active against glioblastomas (GBM) in which the O6-methylguanine-DNA methyltransferase (MGMT) gene is silenced by promoter methylation. Unfortunately acquired TMZ resistance severely undermines its clinical efficacy. Using an in vitro model, we tested whether poly (ADP-ribose) polymerase-1 and -2 (PARP) inhibition could suppress the emergence of resistance to enhance the effectiveness of TMZ. METHODS: Using the MGMT-methylated GBM line U251N, in which TMZ resistance can be induced, we developed a method to rapidly recreate mechanisms of TMZ resistance seen in GBMs, including MMR mutations and MGMT re-expression. We then assessed whether TMZ resistant U251N sub-clones could be re-sensitized to TMZ by co-treatment with the PARP inhibitor ABT-888, and also whether the emergence of resistance could be suppressed by PARP inhibition. RESULTS: U251N cultures chronically exposed to TMZ developed discrete colonies that expanded during TMZ treatment. These colonies were isolated, expanded further as sub-clones, and assessed for mechanisms of TMZ resistance. Most resistant sub-clones had detectable mutations in one or more mismatch repair (MMR) genes, frequently MSH6, and displayed infrequent re-expression of MGMT. TMZ resistance was associated with isolated poly(ADP-ribose) (pADPr) up-regulation in one sub-clone and was unexplained in several others. TMZ resistant sub-clones regressed during co-treatment with TMZ and ABT-888, and early co-treatment of U251N parental cultures suppressed the emergence of TMZ resistant colonies. CONCLUSION: In a model of acquired resistance, co-treatment with TMZ and a PARP inhibitor had two important benefits: re-sensitization of TMZ resistant cells and suppression of TMZ resistance.

A positive feedback loop between Myc and aerobic glycolysis sustains tumor growth in a Drosophila tumor model.

Cancer cells usually exhibit aberrant cell signaling and metabolic reprogramming. However, mechanisms of crosstalk between these processes remain elusive. Here, we show that in an in vivo tumor model expressing oncogenic Drosophila Homeodomain-interacting protein kinase (Hipk), tumor cells display elevated aerobic glycolysis. Mechanistically, elevated Hipk drives transcriptional upregulation of Drosophila Myc (dMyc; MYC in vertebrates) likely through convergence of multiple perturbed signaling cascades. dMyc induces robust expression of pfk2 (encoding 6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase; PFKFB in vertebrates) among other glycolytic genes. Pfk2 catalyzes the synthesis of fructose-2,6-bisphosphate, which acts as a potent allosteric activator of Phosphofructokinase (Pfk) and thus stimulates glycolysis. Pfk2 and Pfk in turn are required to sustain dMyc protein accumulation post-transcriptionally, establishing a positive feedback loop. Disruption of the loop abrogates tumorous growth. Together, our study demonstrates a reciprocal stimulation of Myc and aerobic glycolysis and identifies the Pfk2-Pfk governed committed step of glycolysis as a metabolic vulnerability during tumorigenesis.

Measuring ward-based multidisciplinary healthcare team functioning: a validation study of the Team Functioning Assessment Tool (TFAT).

The team functioning assessment tool (TFAT) has been shown to be a reliable behavioral marker tool for assessing nontechnical skills that are critical to the success of ward-based healthcare teams. This paper aims to refine and shorten the length of the TFAT to improve usability, and establish its reliability and construct validity. Psychometric testing based on 110 multidisciplinary healthcare teams demonstrated that the TFAT is a reliable and valid tool for measuring team members' nontechnical skills in regards to Clinical Planning, Executive Tasks, and Team Functioning. Providing support for concurrent validity, high TFAT ratings were predicted by low levels of organizational constraints and high levels of group potency. There was also partial support for the negative relationships between time pressure, leadership ambiguity, and TFAT ratings. The paper provides a discussion on the applicability of the tool for assessing multidisciplinary healthcare team functioning in the context of improving team effectiveness and patient safety for ward-based hospital teams.

Measuring multidisciplinary team effectiveness in a ward-based healthcare setting: development of the team functioning assessment tool.

Nontechnical skills relating to team functioning are vital to the effective delivery of patient care and safety. In this study, we develop a reliable behavioral marker tool for assessing nontechnical skills that are critical to the success of ward-based multidisciplinary healthcare teams. The Team Functioning Assessment Tool (TFAT) was developed and refined using a literature review, focus groups, card-sorting exercise, field observations, and final questionnaire evaluation and refinement process. Results demonstrated that Clinical Planning, Executive Tasks, and Team Relations are important facets of effective multidisciplinary healthcare team functioning. The TFAT was also shown to yield acceptable inter-rater agreement.

Myopathic dropped head syndrome: an expanding clinicopathological spectrum.

OBJECTIVE: A number of neuromuscular conditions may lead to a dropped head syndrome (DHS), with some patients developing a late onset noninflammatory myopathy affecting only, or predominantly, neck extensor muscles (NEM). The cause, pathogenesis, and nosological classification of this condition are unclear. To further investigate this condition, the authors evaluated the clinical, electrodiagnostic and pathologic findings in seven patients with a myopathic DHS. DESIGN: Analysis of clinical data, electrodiagnostic studies, and muscle biopsies of seven patients, including one set of identical twins, who developed a very late onset myopathy with severe NEM weakness. RESULTS: Age of onset was 61-79 yrs, with the pair of identical twins developing NEM weakness within 1 yr of each other (ages 63 and 64, respectively). Seven patients developed weakness (six slight weakness and one more severe) in muscles other than NEM. The group was characterized by the electromyography (EMG) showing a "myopathic" pattern in cervical paraspinal muscles (7/7), muscle biopsies with nonspecific myopathic changes on histologic stains (7/7), marked abnormalities in NADH dehydrogenase-reacted sections (6/7), desmin-positive sarcoplasmic deposits (1/7), low carnitine levels by biochemical assays (2/7), and mitochondrial changes (3/7). CONCLUSIONS: Myopathic DHS encompasses a wide spectrum of conditions that strongly affect NEM; however, as documented in the monozygotic twins, some patients may suffer from a distinct, genetically determined form of late-onset restricted myopathy leading clinically to DHS.

Subclinical sensory involvement in monomelic amyotrophy.

An 18-year-old woman presented with weakness and atrophy in her hand without associated sensory symptoms, preceding events, or structural abnormalities on neuroimaging. No sensory deficits were detected on neurologic examination. Electrophysiological studies showed not only the expected motor findings for monomelic amyotrophy (MA) in the affected limb, but also markedly reduced sensory nerve action potentials when compared with the unaffected side. These findings suggest that subclinical sensory involvement can exist in patients with otherwise classic presentations of MA.

Health issues of aboriginal female adolescents in Taiwan.

BACKGROUND: The mortality rate and prevalence for some chronic diseases are higher for aborigines compared with the rest of the Taiwanese population. Health professionals in many countries have been concerned with the health of aborigines, but specific health policies for native adolescents have been neglected. AIMS: This paper reports a study comparing the general health status of aborigines and non-aborigine female adolescents, based on school enrollment health examinations. METHODS: A cross-sectional prevalence study with between group comparison was conducted. School enrollment health files were accessed between September 2000 and June 2001. A total of 320 selected female aboriginal students were compared with 237 non-aborigines. RESULTS: With the exception of eye problems, general health status was inferior for the aboriginal female adolescent students. They had lower mean red blood cell volumes, lower haemoglobin concentrations, more oral decay, a greater prevalence of hepatitis B virus carriers and were more likely to be overweight. CONCLUSIONS: It seems reasonable to suggest that health intervention strategies specific for indigenous adolescents should be provided. The design of these strategies should target lifestyle modification and provision of more accessible health information. Health professionals, and particularly nurses, are in a prime position to offer advice and support to this group.

Relationship between attendance at breakfast and school achievement among nursing students.

This survey by correlation study with partial qualitative design examined the effect of attendance at breakfast with school achievement in 710 first-year nursing students at a nursing institute in Northern Taiwan. Dietary attendance cards were scanned by computer before each meal. Since the school is located at a geographically isolated suburban area, this program was compulsory for all first-year nursing students and was included in the tuition fee. Comparison of attendance at breakfast over the four-month semester (from September 1999 to January 2000) and final semester class ranking showed a lower attending rate of breakfast (attendance at breakfast equal to or under 60% of mean times in a 4-month semester) was significantly associated with lower scores on tests in six individual classes and a class rank; while a higher frequency of breakfast attendance (attendance at breakfast equal to or over 85% of mean times in a 4-month semester) was significantly associated with higher scores on tests in six individual classes and a higher class rank (p <.001). To determine the relationships between frequency of attending breakfast and practicing health promotion behaviors, the Chinese Health Promoting Scale was used. We also found that those who skipped breakfast frequently had more negative health promotion behaviors than those who attended breakfast more regularly (p <.001). These results indicate that school achievement is negatively affected when nursing students omit breakfast. The research outcome supports the importance of breakfast in school achievement.